[sts9fan]

Oh really? Didn't hear.

[JDUBS]

15.5 hours!!!

[sts9fan]

 

[Bear]

JW,

I hope you will be exceptionally critical of the Geddes speakers.  I have not seen a review that addressed the quick hf roll-off of the Abbey.  Based on the graphs the Harper would have the most extended HF response while the Nathan has the flattest/smoothest midrange.   Considering that all the designs require subs where is the advantage in the larger higher cost designs?  Another issue with this design is the implementation of the multiple sub protocol.  According to Dr. Geddes nearly any sub will do.  If those subs produces a one-note/peak or dip FR respons  e then the result will be......one note bass and drums etc.?  Perhaps I missed something in his multiple sub approach that addressed the need and subsequent requirements for his sub recommendations.  I would seem a bit arrogant or damaging in the realm of credibility to dismiss the need for quality low FR reproduction and how to achieve/optimize for this.  It would be interesting to hear the waveguides in exclusively without the low FR driver and subs.  It would appear that the midrange in this design has been isolated/focused and all frequencies that fall outside this isolated/focused range are muddied and therefore cause the midrange to be perceived as very clear. 

Playing the role of devils advocate a bit.  Looking forward to your reviews of these speakers and hope that you are able to hear the abbeys(left and right/2channel only) with no subs at low/mid/mid-high/high volumes with music that displays music beyond the range of the speakers capabilities at both ends of the spectrum and then again with the subs alone and then adding the L/R channels back in.

Please be critical and inform us of speakers you have spent a good deal of time with and how they compare in relation to the Geddes design.

[jtwrace]

5.5 hrs

I was sleeping well....

[TomS]

5.5 hrs

I was sleeping well....

Tell Anand to show you the pics I sent him this morning 

[jtwrace]

Tell Anand to show you the pics I sent him this morning 

will do.   

[jtwrace]

< 3 hrs....

Car is loaded and ready!!!

[Letitroll98]

JW,

I hope you will be exceptionally critical of the Geddes speakers.  I have not seen a review that addressed the quick hf roll-off of the Abbey.  Based on the graphs the Harper would have the most extended HF response while the Nathan has the flattest/smoothest midrange.   Considering that all the designs require subs where is the advantage in the larger higher cost designs?  Another issue with this design is the implementation of the multiple sub protocol.  According to Dr. Geddes nearly any sub will do.  If those subs produces a one-note/peak or dip FR respons  e then the result will be......one note bass and drums etc.?  Perhaps I missed something in his multiple sub approach that addressed the need and subsequent requirements for his sub recommendations.  I would seem a bit arrogant or damaging in the realm of credibility to dismiss the need for quality low FR reproduction and how to achieve/optimize for this.  It would be interesting to hear the waveguides in exclusively without the low FR driver and subs.  It would appear that the midrange in this design has been isolated/focused and all frequencies that fall outside this isolated/focused range are muddied and therefore cause the midrange to be perceived as very clear. 

Playing the role of devils advocate a bit.  Looking forward to your reviews of these speakers and hope that you are able to hear the abbeys(left and right/2channel only) with no subs at low/mid/mid-high/high volumes with music that displays music beyond the range of the speakers capabilities at both ends of the spectrum and then again with the subs alone and then adding the L/R channels back in.

Please be critical and inform us of speakers you have spent a good deal of time with and how they compare in relation to the Geddes design.

From a person who had the same questions and who is as new to this CD technology as you, here's what I've learned.  The more expensive designs go lower in frequency with CD, thus more effectively meet the design goals.  The multi subs have to be different in design and frequency response, and then are placed in different types of locations (e.g. one low in a corner, another high on a wall, etc.) in order to spread out and normalize the phase and frequency errors.  Thus there is not a requirement for expensive subs, just different ones.  There's more in this thread:
 
http://www.audiocircle.com/index.php?topic=87428.0
 
As for the other questions, I'm waiting on answers for those as well.

[DougSmith]

... I have not seen a review that addressed the quick hf roll-off of the Abbey.  Based on the graphs the Harper would have the most extended HF response while the Nathan has the flattest/smoothest midrange... 

The Abbey has a gradual roll-off amounting to about 3 db from 2-15 kHz or so.  This actually makes for a more natural sound field than having it absolutely flat out to 15kHz.  I know because I have played around with EQ on mine to achieve both.  The sensitivity of the (adult) ear to frequencies over 12kHz is so poor that I really don't think the response curve above that frequency makes any difference (maybe it does if you are still under 30 and haven't attended too many rock concerts). The high end response can be adjusted, however, by changing one of the capacitors in the crossover.

There isn't much point in listening to the Abbeys without one or more subs if you enjoy full bass response below 100 Hz or so.  Nevertheless, I did that with mine for the first 6 months I had them until I got around to adding a pair of subs.  I liked the sound, but didn't know what I was missing until I heard the system with subs included.  One needs to figure in the cost of at least one sub to be comparing apples to apples against other full range speakers.  Just my 2 cents.

[Bear]

Thanks Doug,

your 2 cents are much appreciated.  I am really interested in system a that can deliver articulate musical bass and drum resolution along with a great midrange.  Who isn't right?  I get the feeling that the Geddes approach discounts the possibility of achieving this in a typical listening enviroment and says the heck with chasing after the elusive/impossible(which it may be) and focuses only on midrange.  This may be my misunderstanding the approach.  In my mind, with little to no understanding of the acousitcs and math, tells me that the multi-sub approach is the way to go but would be better served by starting with subs that deliver quality low FR reproduction focusing on fast articulation and smooth response. As opposed to a many and any subs will do implementation.  Is there just no benefit to attempting to maximize the bass quality(ie.  3 to 4 ob servo subs) or is it a waste of money spent on subs?

[Bear]

Thank you Doug, I was glad to see someone post what you just did. It amazes me what people who have never heard a particular speaker will say about them without any facts to back them up. Your comments on the Abbey are spot on and from experience thank you. Your comments about the HF hearing especially ring true...the vast majority of the people on this forum haven't heard anywhere near 20kHz in 10 years or more. Thanks again Doug for your comments based on real experience,and like you said thats just my 2 cents.

Dan

i hear quite well to 21khz, and then it drops off a cliff.  I should have been more clear in statement about the quick rolloff...it is a gradual slope to a point.  There is not much info up their anyway..other than harmonics.  I am not attempting to bash  the speaker by any means, I am interested, otherwise I would bother probing those that know more than I do.

[dwr]

Bear,
I obviously own a pair of Abbeys and also employ the multi subs (3) with them. On your question of quality subs, I somewhat disagree with Earl on the any sub will do part of it. I used originally 2 (cheapie) subs with a 12" that I built, they were a Velodyne cht-10 and a Yamaha 10" that cost like $100 new. While I saw the big improvement in the overall bass response using these three subs, it  became very obvious to me when I built my sealed 15" and 18" subs and put them in place of the Velodyne and Yamaha, the bass response in my room was then as good as I have ever had. So in "my opinion" having quality subs does make a difference.

Dan

[DougSmith]

Thanks Doug,

your 2 cents are much appreciated.  I am really interested in system a that can deliver articulate musical bass and drum resolution along with a great midrange.  Who isn't right?  I get the feeling that the Geddes approach discounts the possibility of achieving this in a typical listening enviroment and says the heck with chasing after the elusive/impossible(which it may be) and focuses only on midrange.  This may be my misunderstanding the approach.  In my mind, with little to no understanding of the acousitcs and math, tells me that the multi-sub approach is the way to go but would be better served by starting with subs that deliver quality low FR reproduction focusing on fast articulation and smooth response. As opposed to a many and any subs will do implementation.  Is there just no benefit to attempting to maximize the bass quality(ie.  3 to 4 ob servo subs) or is it a waste of money spent on subs?

There are many sub options available.  I would definitely be picky in that department.  An IB with multiple manifolds might be the best option if you can do it.  Otherwise I would recommend two or three bandpass subs.  I built a pair of bandpass subs based on Earl's recommendations (and some of my own research) and am very happy with their performance.  I know someone who has a pair of GR OB servos in his HT who has not been totally happy.  For the best experience, you want something that can effectively pressurize the room. That narrows it down to sealed (requires heavy duty drivers with lots of power - but many folks seem happy with the Rythmic options), bandpass (high efficiency and low distortion in the passband), tapped horns (loud and large), or IB (best low end with low distortion, but think twice about the back wave).

[rave959]

i hear quite well to 21khz, and then it drops off a cliff.  I should have been more clear in statement about the quick rolloff...it is a gradual slope to a point.  There is not much info up their anyway..other than harmonics.  I am not attempting to bash  the speaker by any means, I am interested, otherwise I would bother probing those that know more than I do.

Hi,

I thought the frequency range of human hearing is from 20Hz - 20KHz?   

[dwr]

Rave you are correct, also if you look at Dr Geddes research and especially that dealing with headphones and hearing aids you will see that his research indicates that most people never do hear up to that 20kHz upper limit. Whenever a limit is put on something like that though there will always be some that go above the limit and some that stay below the limit.   

[DougSmith]

Hi,

I thought the frequency range of human hearing is from 20Hz - 20KHz?   

Take a hearing test and find out what your range is.  There are lots of research articles out there that conclude that most people don't hear much > 15 kHz (like this one).

[Bear]

Rave you are correct, also if you look at Dr Geddes research and especially that dealing with headphones and hearing aids you will see that his research indicates that most people never do hear up to that 20kHz upper limit. Whenever a limit is put on something like that though there will always be some that go above the limit and some that stay below the limit.

You can go to a costco that has a hearing aid kiosk/booth in it and if the technician is not busy you may be able to get them to do a quick informal test for you as I did.  The tech commented on my excellent hearing capacity but jokingly noted that most adults she tests are seeing her for reason.

[Letitroll98]

Take a hearing test and find out what your range is.  There are lots of research articles out there that conclude that most people don't hear much > 15 kHz.

+1 there.  I assumed most people on this circle have run frequency plots on their speakers?  However, although I don't hear 20Khz, I can detect it by feeling the pressure wave in my head.  Similar to feeling 20hz bass, but much higher in the body.  In any case, neither extreme has a lot to do with musical notes.

[Bear]

I would add that I had a spot between 16.5-17.5khz I think where I could not hear anything.  Also I don't have any idea how accurate the equipment they use is.

Great info and suggestions regarding your sub experiences.

Very much appreciated.